Electromagnetic Radiation Shielding Assembly

ABSTRACT

An electromagnetic shielding assembly may include a transparent substrate layer and a transparent active layer positioned with respect to the substrate, wherein the active layer is configured to absorb electromagnetic radiation having a first wavelength and emit electromagnetic radiation having a second wavelength, the second wavelength being different than the first wavelength, the active layer includes fluorescent molecules combined with a base material, the fluorescent molecules being configured to absorb electromagnetic radiation having the first wavelength and emit the electromagnetic radiation having the second wavelength, wherein the first wavelength is in a visible electromagnetic spectrum and the second wavelength is in a non-visible electromagnetic spectrum.

FIELD

The present disclosure is generally related to filtering electromagneticradiation and, more particularly, to an electromagnetic shieldingassembly configured to absorb light having a first wavelength and toemit light having a second wavelength.

BACKGROUND

Laser beam generating devices are commercially available as laserpointers and other devices that generate a focused, high power laserbeam. Commercial laser pointers are readily available to the public andare being used to interfere with pilots while in critical phases offlight operations. The laser beam generated by such devices can bedirected at aircraft and reach the cockpit of such aircraft. When thelaser beam interacts with the cockpit glass, the laser beam can bloom orglare on the glass and/or travel to the pilot's eyes, thus interferingwith the pilot's vision. Unfortunately, the number of such laser beamincidents has nearly doubled in recent years.

Pilots must not only see outside of the aircraft, but they also must seetheir instruments without any hindrances. When a laser is pointed at anaircraft, such an incident takes a pilot's attention away from thebusiness of getting passengers safely to their destination. Laserpointers can have a dramatic effect on a pilot's vision, especiallyduring critical phases of flight, such as takeoff and landing. Laserstrikes can also harm a pilot's vision. For example, when a pilot hasbeen piloting an aircraft in nighttime conditions, a sudden, brilliantgreen beam of light directly in the eyes can result in persistent pain,eye spasms and spots in the pilot's vision.

While pilots are instructed to look away from a laser beam or close aneye to avoid the laser beam, by the time the pilot looks away or closesan eye, the laser beam has already reached the pilot's eyes.Furthermore, averting the eyes effectively diminishes the pilot'sability to control the airplane.

Specialized sunglasses can reduce the impact of a laser beam on thepilot's eyes, but these devices also restrict the pilot's ability to seethe cockpit instruments. Other types of sunglasses inhibit a broad rangeof wavelengths of light from reaching the pilot's eyes, which can beundesirable at night and other low light conditions and can be dislodgedduring adverse weather or turbulence only to cause additionaldistraction. Additionally, sunglasses can also be costly when they arein prescriptive form, can cause glare, and are subject to dust and oilbuildup.

Tinted windows suffer from similar drawbacks by inhibiting allwavelengths of light from reaching the pilot's eyes. Auto-dimmingglasses or windows gradually dim and may not block the laser beam beforethe pilot's vision has already been impaired. Additionally, someauto-dimming glass requires a power source.

Existing technologies provide glasses having applied coatings to blockintense light. However, these types of glasses restrict all wavelengthsof light, thereby dimming the appearance of critical flight instrumentsand the external view outside of the cockpit.

Similar problems exist for automobile drivers in sunny conditions orwhen an on-coming car has bright headlight beams.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of shielding optics, such as humanvision, from light interference.

SUMMARY

In one embodiment, the disclosed electromagnetic radiation shieldingassembly may include a transparent substrate layer and a transparentactive layer positioned with respect to the substrate, wherein theactive layer is configured to absorb electromagnetic radiation having afirst wavelength and emit electromagnetic radiation having a secondwavelength, the second wavelength being different than the firstwavelength.

In another embodiment, the disclosed electromagnetic shielding assemblymay include a transparent substrate layer and a transparent active layerpositioned with respect to the substrate, wherein the active layer isconfigured to absorb electromagnetic radiation having a first wavelengthand emit electromagnetic radiation having a second wavelength, thesecond wavelength being different than the first wavelength, the activelayer includes fluorescent molecules combined with a base material, thefluorescent molecules being configured to absorb electromagneticradiation having the first wavelength and emit the electromagneticradiation having the second wavelength, wherein the first wavelength isin a visible electromagnetic spectrum and the second wavelength is in anon-visible electromagnetic spectrum.

In another embodiment, the disclosed electromagnetic shielding assemblymay include an active layer including a transparent base material and aplurality of fluorescent molecules combined with the base material,wherein the fluorescent molecules are configured to absorbelectromagnetic radiation having a first wavelength and emitelectromagnetic radiation having a second wavelength, the secondwavelength being different than said first wavelength.

In yet another embodiment, disclosed is a method for making anelectromagnetic radiation shielding assembly configured to absorb lighthaving a first wavelength and to emit light having a second wavelength,the method may include the steps of: (1) designing a fluorescentmolecule having excitation and emission characteristics in response toelectromagnetic radiation having a predetermined wavelength, (2)providing a base material configured to receive a plurality offluorescent molecules, (3) combining the plurality of fluorescentmolecules with the base material to form a fluorescent composition, (4)forming the fluorescent composition into a transparent active layer, (5)providing a transparent substrate layer, and (6) applying the activelayer to the substrate layer.

Other embodiments of the disclosed electromagnetic radiation shieldingassembly will become apparent from the following detailed description,the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of one embodiment of the disclosedelectromagnetic radiation shielding assembly;

FIG. 2 is a schematic view of the disclosed electromagnetic radiationshielding assembly of FIG. 1;

FIG. 3 is an enlarged view of the electromagnetic radiation shieldingassembly illustrating the fluorescent molecules;

FIG. 4 is a cross-sectional view another embodiment of theelectromagnetic radiation shielding assembly;

FIG. 5 is a diagram of fluorescent excitation and emission spectra of anembodiment of the fluorescent molecules;

FIG. 6 is a diagram of fluorescent excitation and emission spectra ofanother embodiment of the fluorescent molecules;

FIG. 7 is a cross-sectional view of another embodiment of the disclosedelectromagnetic radiation shielding assembly;

FIG. 8 is a schematic view of the disclosed electromagnetic radiationshielding assembly of FIG. 7; and

FIG. 9 is a flow chart illustrating an embodiment of the disclosedmethod for making an electromagnetic shielding assembly configured toabsorb light having a first wavelength and to emit light having a secondwavelength.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings,which illustrate specific embodiments of the disclosure. Otherembodiments having different structures and operations do not departfrom the scope of the present disclosure. Like reference numerals mayrefer to the same element or component in the different drawings.

Referring to FIG. 1, one embodiment of the disclosed shielding assembly,generally designated 10, may include a substrate layer 12 and an activelayer 14 positioned with respect to the substrate layer 12. The activelayer 14 may be configured to absorb electromagnetic radiation having afirst wavelength 16 and emit electromagnetic radiation having a secondwavelength 18. The second wavelength of the emitted electromagneticradiation 18 may be different (e.g., longer or shorter) than the firstwavelength of the absorbed electromagnetic radiation 16. Therefore, theactive layer 14 may absorb electromagnetic radiation 16 at a specificfrequency or range of frequencies and emit electromagnetic radiation 18at a different frequency or range of frequencies.

The substrate layer 12 may include any transparent or substantiallytransparent base material. In one implementation, the substrate layer 12may be a panel of rigid material. For example, the substrate layer 12may be made of glass, acrylic, thermoplastic, poly(methyl methacrylate),and the like. Specific non-limiting examples of the substrate layer 12may include Plexiglass® by Arkema France, Lucite® by LuciteInternational, Inc., Perspex® by Imperial Chemical Industries Limited,and Acrysteel® by Aristech Acrylics, LLC. In another implementation, thesubstrate layer 12 may be a sheet of thin, flexible material. Forexample, the substrate layer 12 may be made of a thermoplastic, such aspolyvinyl chloride, polyethylene, and the like.

As shown in FIG. 2, the active layer 14 may shift the wavelength ofvisible light 16 toward the non-visible spectrum. For example, incominglight having a wavelength in the visible spectrum 16 may undergo awavelength shift and may be emitted as light having a shifted wavelength(e.g., longer wavelength) as it passes through and is absorbed by theactive layer 14.

Referring to FIG. 3, the active layer 14 may include a fluorescentmaterial or composition configured to absorb electromagnetic radiationhaving a wavelength in the visible spectrum 16 (referred to throughoutas visible light or absorbed light) and to emit electromagneticradiation having a wavelength in the non-visible or barely visiblespectrum 18 (referred to throughout as non-visible light or emittedlight). The fluorescent material may include florescent molecules, orparticles, 24 having pre-selected characteristics configured to react toor absorb visible light and emit non-visible light (e.g., infrared lightor ultraviolet light). The florescent molecules 24 of the active layer14 may be encased or encapsulated within a base material 26 forapplication to or upon the substrate layer 12. As such, the active layer14 may be embodied as a transparent sheet having the molecule 24therein.

Thus, in the illustrative embodiments, the fluorescent material (basematerial 26 and fluorescent molecules 24) of the active layer 14 may beany material configured to emit non-visible light in response toreceiving visible light. Various types of fluorescent material may beutilized for the active layer 14. The size of any fluorescent particlesmay be very small, for example, nano-particles or molecules with sizesbetween about 0.5 nm to about 500 nm. The fluorescent molecules 24 maybe any suitable type of molecular composition, including inorganicmolecules, inorganic phosphors, organophosphate, organic molecules,dyes, semiconductor based nano-particles, organometallic molecules,organic-chlorophyll, or other suitable organic or inorganic materials.

Generally, fluorescence is a molecular phenomenon in which a substanceabsorbs visible light of one color (at a first wavelength) and almostinstantaneously radiates, or emits, visible light of another color (at adifferent wavelength). This process is known as excitation and emission.Most fluorochromes may have well-defined bands of excitation andemission. The spectral distribution of emitted light may be largelyindependent of the excitation wavelength. The fluorescent molecules 24of the active layer 14 may be tuned to absorb light having a range ofwavelengths in the visible spectrum and emit light having a wavelengthin the non-visible spectrum, which is invisible to the naked eye. Theactive layer 14 may capture, store, and transform energy fromelectromagnetic radiation and emit energy either through electricalconnectors or through direct emission of electromagnetic radiation. Oncethe electromagnetic radiation is removed, the fluorescent material ofthe active layer 14 may return to an unexcited state capable of beingexcited again to dissipate energy without blocking or interfering withoptics or vision.

In one particular embodiment, the molecule 24 may be an organic moleculehaving a design, or configuration, receptive to various ranges of orsome portion of wavelengths similar to a molecular dye, such as a styryldye. Generally, styryl dyes are organic molecules with fluorescentproperties. Their fluorescent properties may depend on insertion of ahydrocarbon tail into a medium. The length of the hydrocarbon tail maydetermine the dissociation constant for insertion. For example, shorttails (e.g., 43C) may have a high dissociation constant and move fast,while longer tails may have a lower dissociation constant.

For example, styryl dyes, such as FM1-43 and FM4-64 molecules by LifeTechnologies, may be excited by wavelengths ranging between about 430 nmto about 520 nm (e.g., blue/green light). The emission spectrum may beshifted to a maximum wavelength of about 580 nm (e.g., yellow/orangelight) for FM1-43. The emission spectrum may be shifted to a maximumwavelength of about 730 nm (e.g., far-red light) for FM4-64.

FM1-43 is a styrylpyridinium molecule, more concisely known as a styrylmolecule or styryl dye. FM1-43 is an ampiphillic molecule, which hasboth a hydrophilic and a hydrophobic region. FM1-43 has a lipophilictail made up of 2 hydrocarbon chains (e.g., CH3CH2CH2CH2 . . . ) and apositively charged ammonium head. The head may be a pyridinium group andit is made up of two aromatic rings with a double bond bridge in betweenthem, known as the fluorophore part of the dye molecule. The fluorophoregroup has excitation at about 500 nm and emission of light at about 625nm. The lipophilicity of the tail may provide the ability of themolecule dye to dissolve in fats, oils, lipids, and non-polar solventssuch as hexane or toluene. The tail of the molecule is what allows thedye to get into the medium because the positively charged head cannotget into the medium. The interaction of the hydrocarbon tail is whatcauses the change in wavelength.

In another example, the fluorescent molecules 24 may be a type offrequency overlapping molecules providing Frequency Resonance EnergyTransfer (FRET). FRET is a distance-dependent interaction between theelectronic excited states of two dye molecules in which excitation istransferred from a donor molecule to an acceptor molecule withoutemission of a photon. The efficiency of FRET is dependent on the inversesixth power of the intermolecular separation, making it useful overdistances comparable to the dimensions of biological macromolecules.

Referring again to FIG. 1, the substrate layer 12 may include a firstmajor surface 20 and an opposing second major surface 22. The activelayer 14 may be integrated with or positioned adjacent to at least thefirst major surface 20 of the substrate layer 12 to form the shieldingassembly 10.

The active layer 14 may include any transparent or substantiallytransparent base material (a carrier or matrix) 26. The fluorescentmaterial or composition (e.g., the fluorescent molecules 24) may beadded, mixed, bonded, or otherwise combined to the base material 26.Thus, the molecules 24 may be encapsulated (e.g., sealed) within thebase material 26. Encapsulation within the base material 26 may providean airtight environment for the fluorescent molecules 24, keeping themolecules 24 from the atmosphere to prevent degradation of the molecules24. For example, the base material 26 may be a thermoplastic materialthat forms a solid body when cured. As another example, the basematerial 26 may be a binder, or vehicle, that is in liquid form toadhere to a substrate surface and dry as a solid film.

In one implementation, the active layer 14 may be a flexible sheetconfigured to overlay or be positioned adjacent to the substrate layer12. In another implementation, the active layer 14 may be a rigid sheetconfigured to overlay or be positioned adjacent to the substrate layer12. In another implementation, the active layer 14 may be a thin,flexible, solid film configured to overlay or be positioned adjacent tothe substrate layer 12. In yet another implementation, the active layer14 may be a liquefied material configured to coat and adhere to thesubstrate layer 12 and dry as a solid film.

Additional other substrates or coatings may compliment the substratelayer 12 and/or the active layer 14 to provide for tinting, substrateprotection, light filtering (e.g., filtering external ultraviolet light)or other functions.

Another embodiment of the disclosed shielding assembly 10 may includeone or more active layers 14 and no substrate layer 12. The active layer14 may include fluorescent molecules 24 added to the base material 26.The base material 26 may be cured or set to form a durable, solid activelayer 14. For example, the fluorescent molecules 24 may be combined witha substantially transparent thermoplastic or thermosetting polymer basematerial 26. As such, the active layer 14, or a plurality of activelayers 14, alone may be utilized as the shielding assembly 10 in certainapplications.

Referring to FIG. 4, another embodiment of the disclosed shieldingassembly, generally designated 10′, may include a first substrate layer12′, a second substrate layer 28, and the active layer 14′ positionedbetween the first substrate layer 12′ and the second substrate layer 28.For example, the shielding assembly 10′ may be a multi-layered laminate.The active layer 14′ may be sealed between the first substrate layer 12′and the second substrate layer 28 to provide additional protection tothe molecules 26 (FIG. 2) from the atmosphere. It can be appreciatedthat any number of substrate layers and active layers may be combined toform the shielding assembly 10.

FIG. 5 shows an example of a fluorescent absorption (excitation) andemission spectra of the fluorescent molecules 24 of the active layer 14.As illustrated, the molecules 24 may absorb light with a range ofwavelengths (absorbed light 16) and may emit light within a range ofwavelengths (emitted light 18) longer than the wavelengths of theabsorbed light. This transition may be considered an up-conversion sincethe wavelength of the light (electromagnetic radiation) is increased asit passes through the shielding assembly 10.

For example, the active layer 14 may absorb visible light havingwavelengths ranging from about 380 nm to about 750 nm and emitnon-visible light having a wavelength longer than about 750 nm (e.g.,infrared light).

FIG. 6 shows another example of a fluorescent absorption (excitation)and emission spectra of the fluorescent molecules 24 of the active layer14. As illustrated, the molecules 24 may absorb light with a range ofwavelengths (absorbed light 16) and may emit light within a range ofwavelengths (emitted light 18) shorter than the wavelengths of theabsorbed light. This transition may be considered a down-conversionsince the wavelength of the light (electromagnetic radiation) isdecreased as it passes through the shielding assembly 10.

For example, the active layer 14 may absorb visible light 16 havingwavelengths ranging from about 380 nanometers (nm) to about 750 nm andemit non-visible light having a wavelength shorter than about 380 nm(e.g., ultraviolet light).

As such, the disclosed shielding assembly 10 may transform light energythat may interfere with visibility into light energy that does notinterfere with visibility.

More specifically, the active layer 14 may be a laser adaptivefluorescent material including specially designed fluorescent molecules24 that react to visible light having the wavelengths corresponding tofrequencies of commercially available laser pointers. When thefluorescent molecules 24 react to the laser-beam light, the moleculesabsorb light from the laser beam and emit light that does not interferewith vision.

In one example implementation, the shielding assembly 10 may be acockpit window of an airplane and the active layer 14 may absorb laserbeam light directed at the cockpit window and emit non-visible light inorder to allow a pilot to perform any necessary function without visualinterference.

For example, the active layer 14 may be configured to respond to a greenlaser pointer by absorbing visible light having a wavelength betweenabout 495 nm and about 570 nm (e.g., green light) and emitting barelyvisible or non-visible light having a wavelength longer than about 750nm (e.g., infrared light).

As another example, the active layer 14 may be configured to respond toa green laser pointer by absorbing visible light having a wavelengthbetween about 495 nm and about 570 nm and emitting barely visible ornon-visible light having a wavelength shorter than about 380 nm (e.g.,ultraviolet light).

As yet another example, the active layer 14 may be configured to respondto a red laser pointer by absorbing visible light having a wavelengthbetween about 620 nm and about 750 nm (e.g., green light) and emittingbarely visible or non-visible light having a wavelength longer thanabout 750 nm.

Referring to FIG. 7, another embodiment of the disclosed shieldingassembly, generally designated 10″, may include at least one substratelayer 12″ and a plurality of active layers (identified individually as14 a, 14 b, 14 c, 14 d). The plurality of active layers 14 a, 14 b, 14c, 14 d may be configured to absorb visible light 16 and progressivelyshift the wavelength to non-visible light 18.

As shown in FIG. 8, the shielding assembly 10″ may be a multi-layeredlaminate including the substrate layer 12″, a first active layer 14 a, asecond active layer 14 b, a third active layer 14 c, and a fourth activelayer 14 d. Each of the active layers 14 a, 14 b, 14 c, 14 d may shiftthe wavelength of visible light 16 toward the non-visible spectrum. Forexample, incoming light having a wavelength in the visible spectrum 16may undergo a first wavelength shift and may be emitted as light havinga first shifted wavelength 30 as it passes through and is absorbed bythe first active layer 14 a. The light having the first shiftedwavelength 30 may undergo a second wavelength shift and may be emittedas light having a second shifted wavelength 32 as it passes through andis absorbed by the second active layer 14 b. The light having the secondshifted wavelength 32 may undergo a third wavelength shift and may beemitted as light having a third shifted wavelength 34 as it passesthrough and is absorbed by the third active layer 14 c. The light havingthe third shifted wavelength 36 may undergo a fourth wavelength shiftand may be emitted as light having a fourth shifted wavelength (e.g.,non-visible light 18) as it passes through and is absorbed by the thirdfourth layer 14 d.

As discussed above, each of the active layers 14 a, 14 b, 14 c, 14 d mayinclude fluorescent molecules 24 (FIG. 2) being configured, or tuned, toreact to or be excited by light having a predetermined wavelength orrange of wavelengths. For example, the first active layer 14 a may beconfigured to absorb visible light 16 having a wavelength ranging fromabout 495 nm to about 570 nm (e.g., green light) and emit light 30having the first shifted wavelength ranging from about 570 nm to about590 nm (e.g., yellow light). The second active layer 14 b may beconfigured to absorb light 30 having the first shifted wavelengthranging from about 570 nm to about 590 nm and emit light 32 having thesecond shifted wavelength ranging from about 590 nm to about 620 nm(e.g., orange light). The third active layer 14 c may be configured toabsorb light 32 having the second shifted wavelength ranging from about590 nm to about 620 nm and emit light 34 having the third shiftedwavelength ranging from about 620 nm to about 750 nm (e.g., red light).The fourth active layer 14 c may be configured to absorb light 36 havingthe third shifted wavelength ranging from about 590 nm to about 620 nmand emit non-visible light 18 having the fourth shifted wavelengthlonger than about 750 nm (infrared light).

It can be appreciated that each of the plurality of wavelength shiftscan be of the up-conversion type (FIG. 4) to increase the wavelength ofthe light toward the infrared spectrum or the down-conversion type (FIG.5) to decrease the wavelength of the light toward the ultravioletspectrum. Thus, the number of active layers 14 may depend upon the shiftdirection and total magnitude of the shift in wavelength (the number ofshifts in wavelength) to transform visible light 16 to non-visible light18.

The shielding assembly 10″ may form a part of or the entirety of avehicle windshield, a cockpit window, a building window, a heads-updisplay, a lens or the like. The disclosed shielding assembly 10″ may beparticularly beneficial when used in an aerospace application. It iscontemplated that the disclosed shielding assembly 10″ may be utilizedas any substantially transparent surface configured to reduce oreliminate visual obstructions induced by glare on any optics, such as ahuman eye, visual imaging, optical sensors, and the like. It can beappreciated that variations of the shielding assembly 10″ may be equallyuseful in non-aerospace applications, such as automotive, lawenforcement, air traffic control, military, and/or building industries.The active layers 14 a, 14 b, 14 c, 14 d may be applied to the substratelayer 12″ during manufacturing or supplied for retrofitting on anexisting substrate layer 12″.

In an example implementation, the shielding assembly 10″ may include atleast one substrate layer 12″ and at least one active layer 14 a to forma rigid, transparent panel forming a cockpit window, a heads-up display,a helmet visor, or eyeglass lenses.

In another example implementation, the shielding assembly may include atleast one active layer 14 a to form a flexible, transparent sheetapplied to an inner surface of a cockpit window, a heads-up display, ahelmet visor, or eyeglass lenses.

In yet another example implementation, the shielding assembly 10″ may bea rigid, transparent panel positioned between the pilot and the cockpitwindow or heads-up display through which light (e.g., laser beams light)can enter the cockpit.

It can be appreciated that the shielding assembly 10″ may not blockvisible light that the pilot uses to see, as is done by sunglasses andwindow tinting. Further, because the molecule 24 may always be reactingto incoming light within a particular wavelength, there may be no timelag between the light hitting the shielding assembly 10″ and themolecules 24 (FIG. 3) of the active layers 14 a, 14 b, 14 c, 14 dreacting to the light.

Additionally, the florescent molecules 24 (FIG. 3) do not require apower source to operate. As such, the shielding assembly 10″ mayovercome drawbacks associated with light re-active eyeglasses orelectrically dimming glass.

Referring to FIG. 9, also disclosed is a method, generally designated100, for making a shielding assembly configured to absorb light having afirst wavelength and to emit light having a second wavelength. As shownat block 102, a fluorescent molecule may be selected (e.g., designed)having particular excitation and emission characteristics in response toelectromagnetic radiation having a specific wavelength or range ofwavelengths.

As shown at block 104, a base material, or carrier, may be provided toreceive a plurality of fluorescent molecules.

As shown at block 106, a plurality of fluorescent molecules may becombined with the base material to form a fluorescent compositionmaterial.

As shown at block 108, the fluorescent composition material may beformed into an active layer. The active layer may be a transparent solidor a transparent liquid.

As shown at block 110, a transparent substrate layer may be provided.

As shown at block 112, the active layer may be applied to the substratelayer. For example, a transparent, solid active layer may be positionedadjacent to the substrate layer. As another example, a transparent,liquid active layer may be applied to the substrate layer as a coatingor film.

Accordingly, the disclosed shielding assembly may automatically redirectelectromagnetic radiation from a radiation source (e.g., a laser beam)by absorbing visible light and emitting non-visible light withoutinterference and preventing damage to eyesight. Thus, the shieldingassembly may eliminate the need for protective eyewear, which can limitthe vision capabilities of the wearer. For example, when used as acockpit window or heads up display of an airplane, the disclosedshielding assembly may reduce or eliminate the effect of laser inducedglare on the cockpit window caused by laser beam light and protect theeyes of the flight crew during critical phases of flight, such astakeoff and landing, search and rescue operations, homeland securityvideo surveillance, combat operations, and the like.

Although various embodiments of the disclosed shielding assembly havebeen shown and described, modifications may occur to those skilled inthe art upon reading the specification. The present application includessuch modifications and is limited only by the scope of the claims.

What is claimed is:
 1. A shielding assembly comprising: a substantiallytransparent substrate layer; and a substantially transparent activelayer positioned with respect to said substrate; wherein said activelayer is configured to absorb electromagnetic radiation having a firstwavelength and emit electromagnetic radiation having a secondwavelength, said second wavelength being different than said firstwavelength.
 2. The assembly of claim 1 wherein said active layercomprises a flexible transparent film applied to at least one majorsurface of said substrate layer.
 3. The assembly of claim 1 wherein saidactive layer comprises a rigid transparent panel positioned adjacent toat least one major surface of said substrate layer.
 4. The assembly ofclaim 1 wherein said active layer comprises fluorescent molecules. 5.The assembly of claim 4 wherein said fluorescent molecules are dispersedin a base material.
 6. The assembly of claim 4 wherein said fluorescentmolecule is a molecular dye.
 7. The assembly of claim 1 wherein saidsecond wavelength is longer than said first wavelength.
 8. The assemblyof claim 1 wherein said first wavelength is in a visible portion of anelectromagnetic spectrum and said second wavelength is in a non-visibleportion of said electromagnetic spectrum.
 9. The assembly of claim 1further comprising a second transparent substrate layer, wherein saidactive layer is positioned between said substrate layer and said secondsubstrate layer.
 10. The assembly of claim 1 further comprising a secondactive layer positioned adjacent to said active layer.
 11. The assemblyof claim 10 wherein said second active layer comprises fluorescentmolecules.
 12. The assembly of claim 1 comprising a plurality of activelayers, wherein each active layer of said plurality of active layerscomprises a unique fluorescent molecule.
 13. A shielding assemblycomprising: an active layer comprising: a transparent base material; anda fluorescent molecule dispersed in said base material, wherein saidfluorescent molecule is configured to absorb electromagnetic radiationhaving a first wavelength and emit electromagnetic radiation having asecond wavelength, said second wavelength being different than saidfirst wavelength.
 14. The assembly of claim 13 wherein said firstwavelength is in a visible electromagnetic spectrum and said secondwavelength is in a non-visible electromagnetic spectrum.
 15. Theassembly of claim 13 further comprising a second active layer positionedadjacent to said active layer, said second active layer being configuredto absorb said electromagnetic radiation having said second wavelengthand emit said electromagnetic radiation having a third wavelength. 16.The assembly of claim 15 wherein said first wavelength is in a visibleelectromagnetic spectrum, said third wavelength is in a non-visibleelectromagnetic spectrum, and said second wavelength is between saidvisible electromagnetic spectrum and said non-visible electromagneticspectrum.
 17. The assembly of claim 13 wherein said fluorescent moleculeis a molecular dye.
 18. The assembly of claim 13 further comprising asubstrate layer, wherein said active layer is coupled to said substratelayer.
 19. The assembly of claim 13 wherein said active layer comprisesa solid panel.
 20. A method for making a shielding assembly configuredto absorb light having a first wavelength and to emit light having asecond wavelength, said method comprising the steps of: providing afluorescent molecule comprising excitation and emission characteristicsin response to electromagnetic radiation having a predeterminedwavelength; providing a base material; dispersing said fluorescentmolecule in said base material to form a fluorescent composition;forming said fluorescent composition into an active layer; providing asubstrate layer; and applying said active layer to said substrate layer.